Improper Resource Locking vulnerability in Mitsubishi Electric MELSEC iQ-R Series R12CCPU-V firmware versions "16" and prior, Mitsubishi Electric MELSEC-Q Series Q03UDECPU the first 5 digits of serial No. "24061" and prior, Mitsubishi Electric MELSEC-Q Series Q04/06/10/13/20/26/50/100UDEHCPU the first 5 digits of serial No. "24061" and prior, Mitsubishi Electric MELSEC-Q Series Q03/04/06/13/26UDVCPU the first 5 digits of serial number "24051" and prior, Mitsubishi Electric MELSEC-Q Series Q04/06/13/26UDPVCPU the first 5 digits of serial number "24051" and prior, Mitsubishi Electric MELSEC-Q Series Q12DCCPU-V all versions, Mitsubishi Electric MELSEC-Q Series Q24DHCCPU-V(G) all versions, Mitsubishi Electric MELSEC-Q Series Q24/26DHCCPU-LS all versions, Mitsubishi Electric MELSEC-L series L02/06/26CPU(-P) the first 5 digits of serial number "24051" and prior, Mitsubishi Electric MELSEC-L series L26CPU-(P)BT the first 5 digits of serial number "24051" and prior and Mitsubishi Electric MELIPC Series MI5122-VW firmware versions "05" and prior allows a remote unauthenticated attacker to cause a denial of service (DoS) condition in Ethernet communications by sending specially crafted packets. A system reset of the products is required for recovery.